The balloon-carrying women in pink, with hats like wedding cakes, escorted the cowboy into Seattle Cancer Care Alliance. It was July. Sunny. The day of the cowboy’s second stem-cell transplant. As usual, he was carrying a golden egg large enough to hatch a possum.

From every window of the medical building, staff members stared in amazement. William Anderson entered the building, and then the parade dispersed. Like magic. Or the end of a dream.

For Mr. Anderson, turning his trips to the cancer center for treatment into performance art helped him cope with lymphoma. Last Thursday, after a 20-year battle with the disease, he died, surrounded by his loved ones. He was 53.

Mr. Anderson’s quirky sense of humor and zest for living made him unforgettable to those who met him, said his brother, Mark Anderson.

Born into a family of seven children, Mr. Anderson grew up north of Ballard and as a young man in the 1970s rode the rails. His parents feared their son would amount to nothing more than a train-yard hobo. One day, their prodigal son was on his way to register for his father’s alma mater, the University of Washington, when he saw a Ringling Bros. and Barnum & Bailey Circus sign. The next time his family heard of him, he was on the front page of The Denver Post leading an elephant, Mark Anderson said.

After the circus, Mr. Anderson landed at the California Maritime Academy. Andy Coe met him when both were studying to become ship’s pilots certified to work in Puget Sound — an extremely demanding task, Coe said. Mr. Anderson became an esteemed pilot with routes from Brazil to Alaska.

Mr. Anderson’s creativity and humor came to his rescue as his illness worsened, friends and family say.

“He didn’t want to be a sick person who went and got chemo. He wanted to make a production out of it. It made the whole thing a little more human, a little less sterile, a little more magic and a little more fun, even though it was pretty grim stuff,” said lifelong friend Dr. Kevin McCarty.

“A lot of people, when they get cancer it takes over their life,” said Coe. “It becomes what their life is. For Will, it was an inconvenience. His life was about the people around him and the people he met.”

Mr. Anderson always dressed up for his chemotherapy sessions. He went dressed in a gorilla suit, as a Canadian curler, as a very elderly man and once as the oncologist he’d had for 18 years.

One day at the cancer center, Mr. Anderson looked out the window and saw a performance-art group giving away large golden eggs. He rushed out and nabbed one. Afterward he took it to every chemo session and cradled it in his arms as he rode the bus to the center.

Last summer, long after the original performance, a member of the troupe, known as Ooolala, saw him with the egg and learned about the second stem-cell transplant.

On July 16, Mr. Anderson got off the bus to find the pink ladies with the wedding-cake hats waiting. He had his golden egg. They had parasols. One took his arm. They promenaded into the center.

In a blog (inkhunchuckspocket.blogspot.com/) Mr. Anderson wrote to Ooolala: “What a remarkable event you created … Tell your crew that about 100 patients and their teams were just delighted. You told me joy was your product, well you have delivered the goods.”

Mr. Anderson is survived by his wife, Penelope, of Seattle; sons Kinamo and Sam, daughters Jessica and Janise; five grandchildren; his father, Dr. Sam Anderson, of Seattle; brothers, Mark, David and Stephen, sisters Camille Horne, Lisa Crabtree and Christine Stickler. He was preceded in death by his mother, Patricia Anderson.

A funeral Mass will be held 10:30 a.m. Tuesday at Christ the King Church, 405 N. 117th St., Seattle.